Tone modifier for phonographs



F. W. COOLEY.

TONE MODIFIER FOR PHoNoGRAPHs.

y APPLICATION FILED APR.4, 192]. Y l 1 ,423,832, Patented uly 25, 1922.

I VEN T DI?. I F/ffo W. Cop/ AEX Wj* x/l/ Hrw/mfr,

UNITED STATES d PATENT OFFICE.

FRED W. COOLEY, k0F MINNEAPOLIS, MINNESOTA.

TONE MDDIFER FOR PHONOGRAPHS.

Specification of Application filled. April 4,-

To alt whom t may concern.' y

Be it known that l, Finn) YV. Coonnr, a citizen of the United States, residing at lvlinneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful improvements in Tone Moditiers for lhoncgraphs; and l do hereby declare the following to be a full, clear and exact description of the invention, such as will enable others skilled in the art tov which it appertains to make anduse the same.`

This invention relates to sound reproducing machines generally designated as talking machines or phonographs and the invention is particularly directed to the sound chamber or tone arm or tubes of such ma chines.

It is an object of the invention `to construct the tone arms or sound chambers of talking; machines so that an improved tone is produced thereby. n

The invention disclosed in the present application is an improvement upon that disclosed and claimed in my prior Patent No. 1,349,604, granted August 17, 1920, and No. 1,352,115 granted September 7th, 1920. The purpose and object ofthe invention will be readily undertsood from the followingl description made in connection with the accompanying drawings in which like reference characters refer to the same parts throughout the several viewsand in which- Fig. lis a view shwing` the tone arms of a talking machine with the improvement applied thereto; y

Fig. 2 is a section. of the device ofthe invention taken substantiallyon the line 2-2 of Fig. 1 looking` in; the direction of they' arrows; i `j t 4 Fig'. 3 is a similar section with some ofthe parts removed; `and Fig. 11 is a section on an enlarged scale taken substantially on the line 4.--4 of Fig. 1.

Referring to the drawings, the tone arm of a talking` machine which is of ordinary shape, is designated as 1 and is provided at its base with a liange 1, by means of which it is attached to the top of the sound chamberand from said flange ,the sleeve 1b depends in which is fitted the upper end of the tube 2, which tube is adapted to be disposed in the sound chamber of any standard type of talking,` machine and to form a part ot the sound chamber or sound transmitting Letters Patent. Patented July 25, 1922.

i921. sei-iai No. 458,432.

conduit thereof. rlhe tube 2 is tightly fitted into the sleeve 1b and is supported thereby, and this tube, as shown in Fig. 1, may be cut away on an inclined plane at one end, as shown in Fig. 1, to expose a portion of the tube 3 supported therein. Theftube-S has its walls of less thickness than the walls of the tube 2 and said tube is also of less diameter than the tube 2, so that its sides are spaced from the under side thereof. The' tube 2 is clamped at its lower portion to the tube 3, a pad member a being,` interposed between the tubes. Spaced headed and nutted bolts ft extend through a clamping, member 5 disposed oirthe outside of tube 2, and in which the heads of the bolts 4f are shown as beine,`

countersunk, and clampingr plates 6 held in` the inner ends thereof by suitable nuts. The pad a is formed of compressible and yielding material and comprises layers 7 of compressible fibrous material which is preferably leather impregnated with wax. The layers 7 'are secured to the sides of the tubes by' a suitable adhesive. A layer of softer fabric oriibrous material 8, preferably of a material such as soft wool, isr disposed substantially at the center of the pad and sheets of unyielding; or incompressible material 9, which material is preferably mica, are disposed at each side of the layer 8 and the layers 9 are then enclosed between folds of another .piece of waX impregnated leather t l0.` Other sheets of mica 11 are placed atv veach side of the initial folds of the member v10 and are, themselves, enclosed iny outside layers or folds of this member. The outside folds or layers of the members 10 are ad'acentgthe la ers 7 as clearl shown in .l Y Y ,'11 spring member 12 comprising a piece of ,steel wire, such as piano wire, is bent into i the general form `of a hair pin with its bight portion extending,` downwardly and is clamped between the plate G and a pad member o, which pad member contacts with .the inner side of the tube .The spring 12 has its inner ends extending a considerable distance upwardly alonthe inner side of the tube 3 and its free ends are bent inwardly to Contact with the inner surface of said tube, thespring being. placed under tension by the upper bolts e, sol that such endsare held firmly in contact with the tube.` At its lower portion, the spring. 12 is surrounded soy by a layer 13 of the Wai; impregnated leather. The pad L is similar in construction to the pad u disposed bet'u'een the tubes 2 and 3 above described and comprises the central layer of cloth and the alternate layers of mica and leather. will be understood that the spring l2 and tube 3 are thus firmly clamped to the tubo 2 by the bolts l passing through the interposed pad members. its set forth in the prior patents, the nu ts on the bolts Il; can be adjusted to aline the tube 3 concentrically with the tube 2 and, as already stated, the spring l2 is placed under tension by said clamping bolts so that the upper end thereof bears firmly against the innerside of the tube lt will also be noted that the bolts l are surroundcfl at their outer portion and headed portions where the same through the plate 5, with some soft fabric or fibrous material.

lilith the above device embodied in the sound chamber and conduits of the talking machine, a. greatly improved tone is produced. The enact way in which the tube 3 and tension spring l2 in contact therewith act to produce this improved tone is not altogether understood, but that it does improve the saine has been thoroughly determined by me in practice. l have, by long and careful experiments, also arrived at the preferred structure herein disclosed of mounting the spring lf2 and tube 3 to the outer tube 2.

It may be stated that the tubes 2 and 3 are preferably made of Wood. l have secured the best results by making the inner tube 3 of birch and the outer tube 2 of sugar pine, although l d o not Wish to be limited to any specific materials for these tubes. 1When the parts are once assembled with the tube 3 in concentric relation to the tube 2 and the spring l2 under proper tension, the same Will ordinarily not require further adjustment, although the parts may be subsequently adjusted if they have be come disarranged. Such disarrangement Will be indicated by a decrease in the quality of the tone of the machine.

lhile I have described. the p1 rred specific materials used in the structure, l. Wish it understood that any equivalents which may be discovered for these materials are with the scope of the invention and that various changes may also be made in the form, details and arrangement of the parts Without departing from the scope of the invention, which, generally stated, consists in the matter shown and described and set forth in the following claims.

What is claimed is:

l. The combination with the tone arm of a sound reproducing machine, of concentric spaced tubes located Where the sound Waves Will pass therethrough on their way from said tone arm into the sound. chamber of said machine, and a connection between said tubes, said connection comprising a plu rality of layers of yielding compressible inaterial, at least one of the layers of material being of a different degree of compressibility than the other.

2. The combination With the tone arms of a sound reproducing machine, of concentric spaced tubes located Where the sound waves will pass therethrough on their Way from said tone arm into the sound chamber of said machine, and a connection between said tubes, said connection comprising a plurality of layers of compressible material. alternated with thin layers of unyielding material.

8. rllhe combination with the tone arm of a sound reproducing machine, of concentric f'spaeed tubes so disposed that the sound Waves will iL ass therethrough on their Way from the said tone arm into the sound chamber of said machine, a tension spring in contact with the inner surface of the .inner tube, said spring and said inner tube being clamped to tue outer tube, and pads inter posed between said spring and inner tube and said inner tube nd outer tube, said pads being composed of a plurality of layers oi' compressible material at least one of the layers of material being of a different dcgree of compressibility than the others.

il. The combination with the tone arm of a sound reproducing machine, of concentric spaced tubes so disposed that the sound wares ivill pass therethrough on their Way from the said tone arm into the sound chamber of said machine, a tension spring in contact with the inner surface of the inner tube, said spring and said inner tube being' clamped to the outer tube, and pads interposed betiveen said spring and inner tube and said. inner tube and outer tube, said pads being composed of a plurality of layers of soft compressible material alternated with layers of incompressible material.

5. The combination With the tone arm of a sound reproducing machine, of concentric spaced tubes so disposed 'that the sound Waves 'will pass theretln'ough on 'their way' from. the said tone ari'n into the sound chain ber of said machine, a tension spring in contact with the inner surface of the inner tube. said spring and said inner tube being clamped to the outer tube, and. pads interposed between said spring and inner tube and said inner' tube and outer tube, said pad comprising a central layer of soft fabric and alternately superposed layers of incompressible material and soft compressible material.

6. The combination with the tone arm of a sound reproducing machine, of concentric outer and inner spaced tubes disposed so that their sound waves will pass therethrough on their Way from said tone arm into the sound chamber ot said machine, and a conllO nection between said tubes, said connection comprising a pad having a central layer of soft fabric material and superposed layers at each side there of mica and wax impregnated leather.

7. The combination with the tone arm of a sound reproducing machine, of concentric outer and inner spaced tubes so disposed that the sound waves will pass therethrough on their way from said tone arm into the sound chamber of the said machine, a spring element extending substantially parallel to and spaced from the inner surface of the inner tube and having one of its ends bent into contact with said surface, a pad member comprising a plurality of Layers of compressible material at least one of the layers of material being of a different degree of compressibility than the others disposed between said spring and the inner tube and between the inner tube and the-outer tube, and means for clamping the spring, inner tube and pads to the outer tube.`

8. The structure set forth in claim 7, said spring being enveloped at its lower end by a soft compressible material.

9. The combination with the tone arm of a sound reproducing machine, of concentric outer and inner spaced tubes so disposed that the sound waves will pass therethrough ontheir way from said tone arm into the` sound chamber of said machine, a tension spring spaced from the inner surface of the inner tube and having one of its ends in contact therewith, said spring being clamped at its lower end to said inner tube, and a pad disposed between said lower end of said inner tube comprising a plurality of layers of compressible material at leastl one of the layers of material being of a different degree of compressibility than the others.

10. The combination with the tone arm of a sound reproducing machine, of concentric outer and inner spaced tubes so disposed that the sound waves will pass therethrough on their way from said tone arm into the sound chamber of said machine, a tension spring spaced from the inner surface of the inner tube and having one of its ends in contact therewith, said spring being clamped at its lower end to said inner tube, said pad comprises a plurality of layers of compressible and non-compressible material` alternately disposed.

In testimony whereof l affix my signature.

FRED W. COOLEY. 

